I'm loving the wealth of good advice and knowledge being deposited into this thread. But to bring it back on topic a little bit, I'm having a bit of an issue with one of the cables going into my room right now. There's only two cables, and I'm trying to run two machines here. Only one of those cables seems to connect to the switch. I think I can get internet access to both machines by taking an old router and plugging it in to the wall and run it in hub mode but it's really a hack that would be ugly and slow.
I'm fairly sure I have crimped all the cables upstairs (using the unreliable male plug crimping method) and theyre plugged into the switch. At the other ends I have them connected to the female plugs (these dealies
-- though theyre not all these, they are the toolless ones you gotta push down the cap real hard to get the wires in)
So i do know that I used the T568A pinout to connect all of the wall plugs, but there are two cat6-cable ends upstairs in the attic (the two ends of the original 300' cable that got cut up) which are T568B.
My first suspicion was that since this nonworking cable in my room is indeed one of these dark blue cat6 cables it's probably connected to the router with 4 of the pins in the wrong places. But then I wonder, would this cause the cable to show up as "No cable connected" when plugged in? I mean it has all of them, just rearranged, the computer really should be able to tell me that it is plugged in but just can't connect. I guess I'm expecting too much.
I also read that most modern systems will auto detect and account for the use of crossover cables when they are not connected properly, i.e. the hardware will be able to automatically cross and un-cross the cable connecting them. So I was at first thinking, hmm that means I must have screwed up the crimping cuz that means this should just work... then I realized that switching T568A to T568B is NOT the same as having a crossover cable.
So I think I'm going to re-do the plug on the wall now and cross my fingers. Next time I do this I'll definitely get a patch panel
Update: So I changed the wall plug pins and still no cable connected. I really still don't want to redo the entire job upstairs. I need some tools that will let me figure out which cable is which because I don't know which cable in the attic goes to which cable downstairs. In hindsight it would have been terrifically smart to just sharpie some markings on each end of cable before laying it out throughout the house...
I am thinking that I can maybe build a little device that attaches a battery so that the solid wires are connected to the positive end and the striped wires are connected to the other end of the battery. Then I can take a multimeter upstairs and as long as any two solid and striped pairs of wires on the cable go though I will be able to identify it. Other methods i've seen involve some kind of complicated loop which is designed to break if any of the wires fail. I fear if I did that, I'd just get a negative on all the cables and still won't even know which cable is the one needs fixing.
So.... I'm gonna go track down the soldering iron now.
I'm going to make a battery that has a RJ45 male plug, and an LED and resistor on a female RJ45 plug. Gonna use that to figure out which cable goes where in this house.
I found me a lithium ion RCR123A and a little mental math told me this 16ohm resistor would work okay with it considering the white LED drops about 3 volts and by battery is charged to 4V so I ought to get around 60mA through it.
So I found the cable, it is cable number 11... I've got one last crimpable male plug. It's hard for me to believe the factory-made plug is bad. But i've exhausted the other options. I hope this works.
More edit: Oops. the cable was connected when I connected the battery. I hope it didnt kill any circuitry on the switch. Turns out upon closer inspection the end that was there to begin with is covered with little plaster/primer droplets. I'm thinking if I go at it a bit with a knife it will just magically work. If not I can always snip and re-crimp though I think I'd want to switch the damn wall end back to T568A for consistency's sake.
Scraping some of the gunk off of the male tip of the cable did the trick. It doesn't seem like connecting half of the wires to +4v did any damage.